Removing knobs from old receiver (help)

[avionic]

A drop of penetrating oil down that set screw hole.Perhaps.

 

[BUCKETSRB]

If there is something in there and it's part of a broken screw based on your photo and shorten depth of the threaded hole, you can try pulling that knob till cows come home. The only answer is to drill it out, knowing that the internal thread may possibly be damaged or destroyed, but could be re-tapped to a slightly larger size if that's the case. I would first attempt using a left hand drill bit size small enough to enter the hole with clearance to the threaded sidewall to try to remove the object (possibly if you could find a aluminum or brass tubing from a hobby store that slides into to hole leaving a inch or so sticking out that could be used as a guide for the LH drill bit) and with the drill set in reverse using light pressure until you feel it grip the object and rotate it in a CCW rotation to remove it. If that fails then use a regular drill bit and re-tap to the next size, you'll have to open the knob hole for clearance to the larger set screw . The left hand drill bit you may be able to obtain from McMaster-Carr online as well as a larger tap and set screw if needed. Hopefully, you'll find a solution before you have to resort to my suggestion, good luck!

 

[MannyE]

 

[avionic]

 

[fernarias]

They do make screw extractors that small but they're very expensive. I would just cover the faceplate with tape, then I would use a dremmel tool with a cutting disk and basically destroy the selector padle (drilling the grub screw could damage the shaft), and then just buy a new padde on ebay.

 

[brutal]

Bingo ladies & Gentlemen!
The hole's depth is shorter than the other selector
There's something in there!

Is there any way on earth to solve this?
How the hell something like this happened? The hex screws I removed from both selectors are identical, nothing broken...

Just to be clear, you slid the other selector knob back onto its shaft when you performed this depth measurement right?

It's odd because it looks like the setscrew has left marks on the shaft as one would expect.

Use and heat gun or hair dryer and heat the knob up. Some one may have helped you out with glue or epoxy.

Probably can't hurt, just watch the heat near any lettering on the faceplate. Pretty sure that's all inked on.

They do make screw extractors that small but they're very expensive. I would just cover the faceplate with tape, then I would use a dremmel tool with a cutting disk and basically destroy the selector padle (drilling the grub screw could damage the shaft), and then just buy a new padde on ebay.

If heat or a sleeved LH drill bit doesn't do the trick, that's what I'd do. Just split if right down the middle of the screw hole with a dremel thin cut off wheel and replace the knob. Hell, there's probably more than a few of us here with extras.

 

[fernarias]

It's brutal but better than forcing it off. You could damage the selector pot or even the pcb.

 

[eliast]

Guys I have news!

First of all, I'm really sorry but I made a mistake, the depth of the hole is the same in both selectors, Sorry for that.
I finally removed the knob and this is how..
I disconnected the knob's shaft from the mechanism behind the plate

so I could remove the plate with the knob-shaft still on it.
The next step was to clamp the shaft in a vise. So I had the shaft tightened, the plate in the middle and the knob on top.
I then started turning the knob left/right and after some "dust" fell off, it was finally removed! I saw some green stuff on the shaft, so apparently it was oxidized and thus the stuck.

The whole plan was to restore both electronically (recapped etc) and aesthetically this receiver. I've cleaned it as much as I could and I'm having the wooden case restored.
The face plate has some scratches but there's no cure for that... I'm also thinking of replacing the bulbs with led lights and I'm done.

There is a thing that still bothers me and it might sound too much but... is there any way to clean the area inside the VU meter??

There's some more pics:

 

[merrylander]

The meter movements are quite often simply taped to the outer casing with what looks like cello tape (Scotch tape).

 

[eliast]

Yes I can see the tape but I can't remove the inner (secondary) aluminum plate,
I removed the four screws but it's still stiff...

Either way I don't think I can reach inside the VU meter, the front "glass" is part of the meter device itself, it's not part the faceplate (I guess).

 

[Blue Shadow]

Thanks for posting back your solution to the stuck knob. I'm surprised that the removal of the shaft was not mentioned but maybe no one has had that particular issue with one of those knobs before. That was a nice fix, good to have it documented.

 

[ViperZ]

Sorry to revive an old thread, but where do you people buy long metric 1.5mm Allen keys to remove that tuning knob? My Allen key doesn't reach Thank you!

 

[avionic]

Sorry to revive an old thread, but where do you people buy long metric 1.5mm Allen keys to remove that tuning knob? My Allen key doesn't reach Thank you!

https://www.amazon.com/NEEWER®-Titanium-Nitride-Driver-Wrench/dp/B00CP2GGBI/ref=sr_1_3?keywords=1.5mm+hex+driver&qid=1558916463&s=gateway&sr=8-3


https://www.mouser.com/Tools-Supplies/Tools/Hand-Tools/_/N-5ggb?Keyword=hex+driver&FS=True

 

[avionic]

I got mine from McMaster-carr
Order a 1.5mm and a 2mm

these are the most common for knobs.
https://www.mcmaster.com/orders

 

[ViperZ]

Thank you very much!
So close, but so far for me to remove that front panel lol. Will run to the local tool store tomorrow morning. If nothing there, will get a set from Amazon.

 

[Oerets]

I was able to straighten out one enough to reach.
Then with pliers loosen the screw from the bottom IIRC.